


Knowing Your Strength and Potential is Only Half The Battle

by DeathsLastPrayer



Series: Being A Superhero Doesn’t Always Mean You Feel Super But Saving People Makes It Worth The Trouble [1]
Category: Shingeki no Kyojin | Attack on Titan
Genre: AU, Alternate Universe - My Hero Academia, End game pairing is my usual, I'm sorry in advance for part three..., M/M, Quirks, Series of chapters, WIP, Worldbuilding
Language: English
Status: Completed
Published: 2017-08-20
Updated: 2017-08-20
Packaged: 2018-12-17 19:19:41
Rating: Teen And Up Audiences
Warnings: Graphic Depictions Of Violence, Major Character Death
Chapters: 1
Words: 4,568
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/11858001
Author URL: https://archiveofourown.org/users/DeathsLastPrayer/pseuds/DeathsLastPrayer
Summary: In Which: Eren navigates through life, lessons, and loss while growing into his Quirk. There's also the bit where he'll have to accept himself for who he is and who he'll become but, that's easier said than done.Set in the Boku no Hero Academia/My Hero Academia Universe... Kind of... Or, well, SnK/AoT borrows their world for a bit.





	Knowing Your Strength and Potential is Only Half The Battle

**Author's Note:**

> Welcome, welcome... Let's see if I can pull this semi-crossover (Not really a cross-over, though) off lol!
> 
> OH!!! WARNING!!! I'm not sure if this is a trigger but there's parental death in this fic, so... yeah. Just in case. Also, mild suicidal thoughts. It all takes place in Part III of this chapter.

* * *

##### 

I. 

* * *

“You’re very special, Eren. You understand that, don’t you?” 

Four year old Eren stares with big eyes and shakes his head, “No.” He mumbles because he doesn’t understand. Not even a little bit. Sure, he has a quirk but he’s not like Supersonic or Ultra –they’re special. The best heroes ever. Heroes that he wants to be like when he gets big but he’s not anymore special than any other person with a quirk. Which he says as best a four year old can. 

His father just smiles, “Well, you are. You were born with a rare and fantastic quirk: empathy. Do you know what that means?” 

Eren’s nose scrunches and his lips twists, “I sometimes has the same quirk as mommy and daddy and ‘Kasa and Min-min?” Because he does. 

First, he just has his mommy’s telekinesis and then he finds out that he can talk with his mind like his daddy. But, when he and Kasa and Min-min were at the park not too long ago, he accidentally broke the slide when he jumped too hard (Kasa’s super-strength) and he cut his leg but it was okay because his boo-boo patched up in seconds (just like her’s). And he has a memory like Min-min’s sometimes –like when they’re reading and he can remember everything. Every word and detail down to comma placements and watermarks and page numbers with specific scenes or sentences. 

So he kind of understands his quirk but it only works when he’s with those people and then it goes away and he feels nothing. Except for the quirks that are like his parents because those never go anywhere. Which really doesn’t make him that special if his quirk comes and goes without his say so. 

“Hmm… you’re still very special, my son.” Grisha takes a second to pick his son up and sit the boy on his knee. “Once you learn how to control it, you’ll be able to retain every quirk you come into contact with. That means infinite possibilities for you –the mixing and matching of dozens, hundreds, or thousands of quirks. Whatever your mind can think of.” His smile softens when he stares into big, dewy, green-blue eyes, “Right now, you can freely use your mother’s quirk and my quirk –we made you and have been around you longer than anyone else so those are probably the easiest quirks to call forth. But that doesn’t mean that the quirks from Mikasa or Armin or other children you might have come into contact with –it doesn’t mean that their quirks are not there. You’ll just need to practice to control them and use them at your own convenience.” 

“But mommy told me that I needa be careful with my quirk cuz it’s- it’s-” Eren pauses and frowns and glances at his shoes. “It’s dangerous.” 

Hmm… well, that’s true but not for any of the reasons that his son is thinking about. “It’s dangerous if others find out about your unique quirk right now, yes, but you’re not dangerous. And you won’t be. Your mother and I- We’ll make sure you learn how to control your quirk and when the time comes, you’ll be able to use it wisely. Become a proper hero. In the meantime, let people believe that your only specialty is the telekinesis your mother gave you.” 

Eren’s lips purse because it sounds like his daddy wants him to tell fibs after telling him all four years of his life the complete opposite… 

“I’m not asking you to lie, just to omit certain aspects of the truth. For now. It’s to keep you safe but you’ll understand when you’re older.” Grisha stands and carries Eren with him, “For now, only use your extra quirks at home, promise me.” 

His mommy and daddy don’t lie so Eren’s immediate response is, “Promise.” He can do that much. 

Except, they come to find out that it isn’t quite that simple because Eren has no control over his quirk or the quirks from the people he comes into contact with. Even though there are more quirkless people in the world than not, there are still quite a few with quirks. Quirks that Eren doesn’t know how to control or hide or absorb properly. 

And once he enters kindergarten and is surround by a wide variety… well… that’s when he learns a lesson not meant for a child. 

On the very first day of class when all of the children play in the courtyard before the teacher ushers them in, Eren is overwhelmed by the onslaught of quirks that come into contact with his little body and he explodes (absorbs a combustion quirk from someone that mounts a top all of the others). After exploding, he passes out and regenerates and scares staff and students alike. Eren wakes up terrified and worried and bawling his eyes out because he broke his promise and he might’ve hurt someone but- but. But his mother tells him that it’s okay. Everything will be okay. 

That’s when his parents decide that it’s best if they move to the countryside until their child has a firm grasp on his quirk. 

It’s for his own safety. 

  


* * *

##### 

II. 

* * *

  


He meets them when he’s six –a man and a boy that change his life forever. Not right then and there but, they end up being the catalyst to a lot in Eren’s life so… meeting them is a pretty big deal when it happens. 

It’s an accident when he stumbles upon them or finds them or hears them… Eren’s not really sure how to classify it but he’s the one who saves them. 

On a boyish whim. 

It starts with his mom being a nag about his farm chores and “getting the barn in order before the storm rolls in”. Eren complains because he can do the job just fine from his room (can insert the command “barn” right into their minds and the cows will listen). But, no. For reasons that he won’t ever be able to explain, his mum wants him to act like a “normal” child (only when it comes to chores) –wants him to get outside and move around and break a sweat or whatever. He thinks it’s the stupidest thing but he listens to her (mostly). So he trudges out to the pasture to do as he’s told (and if he cheats by using his telekinesis a little or his mental manipulation, no one has to know but him). 

And- fine. His mom was right about getting outside because the calm before a storm is pretty and the cows like to talk about the pigs and- yeah. Eren is kind of having fun. 

Except, he can hear someone crying and some murmuring or humming or both and it grates on his mind because he still can’t control the hearing quirk that he got from the mailman a year ago. Trying to ignore it does nothing for him and he does try. Tries so, so hard to ignore it but- 

But the childlike voice gets picked up by the wind –gets louder- and it keeps whining in between wails and sniffles, “ _Papa… Papa… please wake up!”_

And a weak but confident voice keeps mumbling, “ _It’s’kay… ‘m okay…”_ periodically. 

That guy doesn’t sound okay. 

None of that sounds _okay_. 

So Eren can’t just stand there unintentionally eavesdropping. And really hearing them makes him feel like a jerk for trying to tune them out… especially when he can help or could have helped from the start. His quirk is built for him to do just that. 

But… but his mommy always tells him to stay close and to mind his own business and to not recklessly use his quirk but… 

But if he wants to be a hero, he has to help when he can. 

And what kind of a future hero would he be if he couldn’t even help the people that are nearby? A shitty one. So he’ll help. 

Unlucky for the people he’s going to rescue: they’re in the middle of nowhere Kansas. 

Lucky for them: they’re a few miles South of the barn… off the road by the cornfields if Eren is guessing right. Still on Jaeger property too. And his parents are doctors so… 

So his mum will (hopefully) understand when he brings them back to the house and she’ll definitely understand why he has to use his quirks and break the promise about using ‘em in front of strangers and- 

“ _Papa!”_

She’ll understand. 

  


* * *

* * *

* * *

  


The unconscious “dad” turns out to be Erwin Smith (aka Ultra) _–thee_ Ultra. In the flesh. Eren can’t get over the fact that he’s the one who rescues one of the men that he admires most in the world. And he gets there just in the knick of time because Erwin passes out due to blood loss and a near fatal wound but he’s not called “Ultra” for no reason. The man has Mikasa’s raw power and a will that diamond can’t cut through. 

It’s the “will to live” that saves his life. 

That, and Eren. 

Or maybe Jean –the son. The son that blames himself for his dad’s injury. The son that accidentally tells the wrong person who his dad is because he feels like bragging about something since he can’t brag about himself. The idiot, crybaby, liability of a son that paints the target on his dad’s back because he feels like boasting and showing off something because the other kids think he’s quirkless and ruin his self-esteem a bit so… So the son with the weird quirk that mutes quirks almost (kinda) kills his papa and confuses the hell out of Eren who’s never experienced being without his quirks before. 

And Eren wants to not like him. He really, really, wants to. Not like him that is. 

But he can hear Jean’s thoughts now that they’re apart. Probably could’ve heard them anyway because they’re so loud that he can’t block them out and then they’re so vibrant that they end up a stream of emotion. Regret. Sorrow. Unease. Unhappiness. Terror. Terror. Crippling terror… yeah. Eren can’t hate the kid for getting his hero hurt by doing something so dumb, not when the kid hates himself enough for everyone at the moment. 

It’s kind of… heartbreaking. 

Makes Eren want to shut out all of the extra noise but the hearing and mind reading quirk are at this weird stalemate of a blend where they amplify each other. A temporary confusion of the senses is what his dad calls it. So he can’t blot Jean out like he wants to. 

Not unless he wants Jean to do it (which is kinda cool when he really thinks about it). Except, Jean is wearing the restrictors so that he can sit with his papa. 

There’s that. 

Sadly. 

“ _Which means that you can do the noble thing and at least cheer him up, perhaps. You’ve certainly been on a roll today with regards to being a hero so what’s adding one more thing to the roster.”_

Eren frowns. He hates it when his dad invades his thoughts and he can’t wait until he’s strong enough to block him out too. 

“ _Not in my lifetime, brat.”_

Eren’s lips purse and he stops thinking altogether. He just walks down the hall to the guest room and knocks before letting himself in. “Hey…” Jean’s head shoots up and Eren feels this urge to hug him because he looks like he needs one with those swollen eyes and that bright red face… “My dad says your dad’s gonna be sleep for a while so… I um… I just got ‘Batman: The Animated Series’ Blueray collection in the mail… Wanna watch it?” 

“I- I should wait-” 

“My mum is gonna take care of your dad now and she’ll let you know as soon as he wakes up. I mean, you can trust us. Or, well- you can trust the kid who saved your life.” And he doesn’t mean for that to come out sounding cocky but, after the day that guy has had, trust is a big issue. 

Jean bites at his bottom lip and stares at Eren with expressive honey eyes. Jean’s thoughts are so loud but Eren focuses on ignoring them because that would be cheating. It’d be the complete opposite of establishing trust- “Okay. Just- promise she’ll get me as soon as he wakes up.” 

Without hesitation, “Promise.” 

* * *

##### 

III. 

* * *

For all it’s worth, the world could have ended on his tenth birthday and Eren wouldn’t have bat an eyelash. No feelings would have been felt. No pain. Nothing. Just an emptiness spurred on by the slaughtering of his mother and father right before his very eyes and then the blinding terror followed by a noxious rage and then the darkness… 

The world ends on his tenth birthday. 

And _that_ … _that_ leaves him devastatingly numb. 

Changes everything he knows and everything he thinks he knows. 

Four weeks after his tenth birthday, Eren wakes up to bright white and the putrid stench of antiseptics. He blinks open bloodshot eyes and feels the rush of all of his acquired quirks surging through him. Blinks and the world mutes. By this point in life, he has a general understanding of controlling and juggling and fusing his various quirks but the ones his parents gave him… those are ingrained into him like the absolute functionality of an organ and he can never mute them. 

Never. 

Especially not now. 

So it hits him –the reality of the situation. It isn’t a dream or conjured fabrication of memory or a story from old recalled and relived. Seeing his parents get murdered really happens. 

And he lives. 

So it hits him and it hits really, really fucking hard. That unyielding flood of emotions compressing with reality that gives way to a full body jerk. Makes the entire building shudder when he sits up and wails. The lights shatter and the walls begin to crack as the building violently trembles and there are hands on him that startle before he’s pricked by something sharp. 

The world fades to black. 

  


* * *

* * *

* * *

  


Eren never realizes how famous his dad is until his dad is dead. Yes, he knows that his dad _was_ a doctor who specialized in working with the quirked. And, yes, he knows that the man _was_ a damn good doctor because celebrity heroes swear by him and used to come to their home often enough and- yeah. Eren knows all of that because he saw it or heard it or both. 

He knows his dad is the shit. 

But (and it’s one of those big and overwhelming “buts”), he’s been raised in bumfuck nowhere Kansas on a big ass farm where he was home schooled with his only constant friends being the animals (or Armin and Mikasa who would come over for holidays and summers). Jean too… kind of (that’s on of those complicated “friendship turned rivalry” situation). Newspapers kept him updated about the world –outside of comics and video game references or picking the thoughts of those around him (which his dad always… his dad always got a little mad about that but… yeah). 

Apparently, his dad is- was big shit for being both a kick ass doctor AND an unparalleled researcher in the field of quirks and quirk restriction or some bullshit that Eren doesn’t really give two shits about at the moment. But he remembers a bit about it because his dad made him some bracelets to help him control his quirk –made it easier to adjust the strength of some abilities as opposed to others and what not and- 

And he knows a little bit. 

Knows more about that aspect of his dad’s life in the last fifteen minutes because damn near everyone crowded into his stupid fucking hospital room keeps thinking about the research or openly talking about it. About lost fucking studies and experiments and opportunities when his dad is… his dad is dead. 

For how long now, he’s not sure, but not nearly long enough for people to be so… fucking disrespectful with regard to a life and- and Eren feels sick to his stomach. 

Sicker when the topic of who gets to _keep_ him weaves in to the conversation. 

Which is total bullshit because _nobody_ gets to _keep_ him. 

Eren has Armin’s memory and he knows for a fact that his parents had a will. His mom and dad specifically showed it to him and explained it to him, which is when he decides to stop feigning sleep because it’s long overdue for the shit show and pissing contest to end. “I’m Erwin Smith’s ‘fucking problem’.” The entire room quiets to a dull murmur of vapid thought that makes him nauseous. 

Can still “hear” people calling him a variant of “brat” and “bastard” or bad mouthing his parents but he’s too tired to shut that particular quirk off at the moment. Still… the way they’re speak of his _dead_ parents makes him more livid than anything that they could ever say about him- 

Levi steps forward and rest his hand on the railing of the hospital bed, dark eyes cold as his gaze drifts around the room. “You heard him. And by the end of the day, there’ll be the documentation to back up his assertion. Until then, everyone get the fuck out.” That tone leaves no room for anything and makes Eren coil inwards a bit. 

More so because he can’t read Levi’s mind. Not one bit. 

Never could. 

The only other mind he could never freely touch was his dad’s- 

“First things first,” Onyx eyes survey Eren carefully as Levi walks over to shut the door before leaning against it, arms folding carefully over his chest. “Erwin is on his way here and he’ll be bringing you home. I’m second to him when it comes to guardianship of you, so there’s that.” Dark eyes study Eren momentarily before Levi decides to rip the band aid off. “Next order of business, it’s best if you acknowledge here and now that Grisha and Kalura are dead, however, that bit of knowledge doesn’t warrant a tantrum like the last one you had when you woke up three days ago.” 

Ah… so that happened three days ago. Eren’s sense of time has been warped since _that day_. But what’s the point. 

Time doesn’t matter. Dates don’t matter. Nothing matters. 

Nothing. 

“ _That_ ,” Levi levels Eren with his pitiless glare. “That pity party you’re giving yourself right now, stop that shit. Your parents are dead but life goes on. The world keeps moving. You’ll keep moving because you have no choice.” 

White hot anger simmers and sloshes through Eren’s veins when he hears those words. They pierce and prod at his shredded heart and if the room vibrates, he blames his… emotions… vibrates…? Blue-green eyes glance down and a frown curves dry lips when he catches sight of the black manacles on his wrist. Nine of them clipped around his left- 

“That makes explaining the next part simple. After you nearly destroyed the hospital, I had to put those on you.” Levi walks across the room, eyes focused on black bands. It took nine quirk restricting bracelets to contain the abilities of one child and even those have barely put a dent in Eren’s power. That is simply a fact. One that he alone is privy to because Eren has yet to conceptualize the extent of his extraordinary ability… All for the better as things stand. “It’d be wise to be mindful that the only quirk registered under your name is the telekinesis. It’s to be the only quirk attached to your name for as long as time provides, if you know what’s good for you, that is. That quirk alone is a SSS-Level quirk so can you even imagine the complications beholden to us, more so yourself, in the future if people were to discover that you-” 

“Have an empathic quirk. I know.” Because he does. His mom and dad drilled that into him nearly every day of his god given life. 

Levi’s lips twitch, “Very well. Then we’re on the same page about that at the very least. As to the third order of business, you’ll be living with Erwin but Mikasa and I are only a few doors down. You can consider my place as much of your home as his. In addition to moving and picking up the pieces, you’ll begin attending an actual academy for the quirked next month.” 

“But school-” 

“You’ll be fine. Those bracelets were specifically designed by your father with you in mind. They’re supposed to help you manage your quirks and to keep them under control. In fact, I’ll be adding four more-” 

“Thirteen!” If he sounds incredulous, it’s because- because he’ll be virtually quirkless and that’s- 

“That will make you a normal child while you go through this grieving process. Neither I nor Erwin have the time to deal with your tantrums and outbursts. However, when you begin school, we’ll reduce the number to six –just enough restriction to allow you to absorb new quirks but still not enough for you to overload… lucky for you, Grisha has always been very detailed and descriptive with his research pertaining to your particular quirk restrictions and dynamics. Even your mother’s.” 

Eren recoils when Levi mentions his mother. Without his say so, his mind drags him through the memories of the last time she was breathing. That moment when she was flush and smiling and bringing his cake out to the patio. The instant she glanced at his dad and the smile began to slip. Those unbearable seconds as reds and pinks splattered across everything because she- she just- 

“Hey. Come back to me!” 

The command followed by Levi’s hand in his hair jolts Eren from those thoughts. Makes him realize that he’s trembling. Trembling and crying. He swipes at his face with his right hand and tries to breathe… in. Out. In. Repeat. 

“Last order of business before I head out to deal with those annoying fucking bureaucrats: did you see the person that murdered your parents?” The hot topic of the hour but integral to solving a world-class case. 

“I…” Those memories hurt and he can’t- those aren’t- 

Levi, for once, looks sympathetic and understanding. “I know this is hard for you, however, this information is important. Anything will help.” 

It hurts so much to remember but Eren does. No matter how much he doesn’t want to. It’s surprisingly easy to hone in on Armin’s Quirk and force himself to shuffle through mental images that will haunt him until the day he utters his last breath, although, there’s a blank space after his mother spontaneously combusts… “I- It’s all hazy and I just remember dad telling me to fade and then I blacked out but- but mom exploded and dad was… was ripped apart like paper in an instant and-” And Eren can’t breathe. He absolutely can’t find his breath and the room is spinning- 

“Hey,” Levi slaps him one good time, “Focus!” Two more bracelets join the others. 

Makes Eren feel boneless. 

“You did well being able to say that much. Just know, the case is being handled by Erwin and myself personally.” 

When he finds the energy to snort, even Eren’s amazed. What good is an investigation if it won’t bring either of his parents back. Which he says and then he follows it by, “I wish I were dead too.” Because he does. 

Because the way he hurts is just too fucking much and he’ll never be able to forget anything about that day or them or the life he lived before so what’s the point of living at all. 

“You’re far too young for that sort of defeatist behavior. Especially when you have cause to live. Didn’t a three-year-old version of yourself once tell me that you wanted to be the greatest hero this world has ever seen? Didn’t you say you wanted to surpass myself and Erwin? That you would one day be able to read Grisha’s mind and make Kalura’s telekinesis collapse? Those are still viable goals, however, if those don’t suffice, live to avenge them.” Revenge as a reason to live is a tricky concept but Levi needs something to work with, to keep the kid grounded. After all, Eren’s his ward too. They’ll manage. “Live for the sake of your slain parents.” 

Living for his parents… for revenge… there’s a thought. One that makes the room seem far less dull than it did moments ago. It’s a goal that makes so much sense because he’s strong, or will be. Can be. _Limitless_ is what his father always told him. 

“Fine.” He’s sure he can do that. Can grow and learn to wield his quirk for the purpose of demolishing the person or people responsible for destroying his perfect world. 

So- yeah. The world ends on his tenth birthday. 

But Eren will live –will obliterate anyone who gets in the way of rebuilding and perfecting the new world he’ll force himself to be a part of. 

“Good to hear. We’ll talk later, for now, rest up.” 

Eren’s already yawning as Levi slips out of the room. He’ll focus on world building tomorrow. For now, he wants to enjoy that numb feeling for a bit longer because facing his emotions is going to be a son of a bitch. 

  


* * *

* * *

* * *

  


“A combustion quirk and a- what? Shredding quirk?” 

“You saw Grisha’s body before anyone else and something along those lines would fit Eren’s description.” 

“Two assailants. Two that neither Grisha nor Kalura were prepared for, which is a surprise in it of itself.” 

“A cloaking quirk in addition to the other two and teleportation. Teleportation or… a portal quirk, perhaps, given the lack of vehicular evidence. Multiple villains were certainly involved. What they were after-” 

“Eren. Grisha keeps little more than medical supplies at home-” 

“And he goes through great lengths to keep his family out of the limelight, which means that it’s someone who knows a bit about him. The person who organized this is clearly in his immediate circle.” 

“Tch… how troublesome…” 

“At the very least, between the two of us, Eren will be safe.” 

“Once that child learns how to fine tune his initial quirk, he won’t need us, or anyone else for that matter. He’s dangerous.” That’s simply reality. A fact. 

“A danger that will better the world so long as he’s cultivated with the best possible care. The perfect hero.” 

“If you believe so, I have no choice. But I’ll also be prepared to eliminate him if things don’t go according to yours or Grisha’s will.” 

“Cold, even for your cynical world views.” 

“Not cold, I simply value the many as opposed to the few.” 

“You say that now but just wait, Levi. Being a parent will change you.” 

“Taking in Mikasa was quite the change as it is. You’re the one that’ll have to handle two brats with opposing quirks.” 

“Do feel free to help whenever you have a hand to spare. In fact, you’re quick enough to always spare a hand.” 

“Yes, yes… I’ll be around. But remember, he’s _your_ pillar of humanitarian hope.” 

“That he is.” And has been since the day one Eren Jaeger single handled saved his life and the life of his child. 

* * *

**TBC**

* * *

**Author's Note:**

> Sorry about the... death. And the mild description of such! I hope you all enjoyed otherwise. Anywho, if you dug it, drop me a line or hit that kudos button! Thanks for reading!


End file.
